Comprehensive device mismatch SPICE model for advanced technology nodes

摘要

Device mismatch is one of the key parameters for the design of high-precision circuits since parameter variations limit circuit performance. Basically, the device mismatch is modeled by the classic Pelgrom's model in which the mismatch has L(-0.5)*W(-0.5) dependency. This model indeed satisfied industry needs for a long time. However, in practice, this may not be true especially for advanced technology nodes with more complex process steps. In literature published in recent years, one model different from the Pelgrom's model was proposed considering the short channel effect on matching degradation, and another one studied the impact of halo implantation on mismatch performance. In this paper, the mismatch compact models are first reviewed. Then, a comprehensive yet simple SPICE model is presented to cover various process effects on mismatch performance. In our model, the length and width dependency are modified with different exponent so that the mismatch is proportional to L(-nL)*W(-nW), where nL and nW are parameters to be extracted from experimental data. Examples are provided to show the capability of the new compact model.